The term "triplexed" is recognized by Code as a cable assembly... and nothing more. This does not mean that a triplexed conductor cable assembly is automatically identified. Being identified requires each member conductor to be identified as suitable for the purpose.
I am using the NEC definition in 396.2:
2011-NEC said:
396.2 Definition
Messenger-Supported Wiring. An exposed wiring sup-
port system using a messenger wire to support insulated
conductors by any one of the following:
(1) A messenger with rings and saddles for conductor sup-
port
(2) A messenger with a field-installed lashing material for
conductor support
(3) Factory-assembled aerial cable
(4) Multiplex cables utilizing a bare conductor, factory as-
sembled and twisted with one or more insulated con-
ductors, such as duplex, triplex, or quadruplex type of
construction
I am using the term Identified as defined in art 100:
2011-NEC said:
Identified (as applied to equipment). Recognizable as
suitable for the specific purpose, function, use, environment,
application, and so forth, where described in a particular
Code requirement.
Now the cut sheets posted in the links earlier meet
.. power cables .. that are
identified for the use T396.10(A).
I consider triplex a covered conductor as permitted by 225.4:
2011-NEC said:
225.4 Conductor Covering
Where within 3.0 m (10 ft) of any building or structure other
than supporting poles or towers, open individual (aerial)
overhead conductors shall be insulated or covered. Conduc-
tors in cables or raceways, except Type MI cable, shall be of
the rubber-covered type or thermoplastic type and, in wet
locations, shall comply with 310.10(C). Conductors for fes-
toon lighting shall be of the rubber-covered or thermoplastic
type.
Exception: Equipment grounding conductors and grounded
circuit conductors shall be permitted to be bare or covered
as specifically permitted elsewhere in this Code.
Definition of covered:
2011-NEC said:
Conductor, Covered. A conductor encased within material
of composition or thickness that is not recognized by this
Code as electrical insulation.
Triplex as defined by 396.2 (3) or (4) includes the ambiguous term "cable" as well as 225.4. There are two uses of the word cable; "cable" and "in cable". They are not the same meaning or definition. The word cable in 3 and 4 means a grouping of conductors, not covered by any outer jacket. "In cable" as used in 225.4 means a covering the conductor could be in, a an outer jacket or sheath, like SER, NMB or UF cable.
I went with the first paragraph just "insulated conductors".
If we want to just call "in cable" and "cable" the same meaning triplex would have comply with the 2nd part of 225.4 thus 310.10(C), thus be listed.
310.10(C):
(C) Wet Locations. Insulated conductors and cables used
in wet locations shall comply with one of the following:
(1) Be moisture-impervious metal-sheathed
(2) Be types MTW, RHW, RHW-2, TW, THW, THW-2,
THHW, THWN, THWN-2, XHHW, XHHW-2, ZW
(3) Be of a type listed for use in wet locations
Now we are back to listed which we can all agree it is not, well OK except for this:
http://www.awcwire.com/ProductSpec.aspx?id=XLPE-Power-Cable-UL-RHH-RHW-2-USE-2
but that is the only one I found that is UL listed "UL 44 Type RHH/RHW-2
UL 854 Type USE-2"
Most of the major mfr's triplex is identified not listed.
If requiring it to be listed is hinging on "cable" {396.2 (3) or (4)} and "in cable' {225.4} having equal meaning, it could be argued that they are unenforceable and ambiguous terms, we would have to explain why CMP4 did not put a code section like 310 next to "other" in T396.10(A) and how that could not be construed as "specifically elsewhere in the code" {310.1}.
And explain the dangers it has if utilities use it all the time.
If triplex is identified "covered conductors" supported on a messenger then that last paragraph of 225.4 does not apply and the triplex only has to be identified as defined above, not listed.
As I said the cut sheets meet the requirement for identified.
Refer to the cut sheets I posted links to above.
As stated by 310.1 "These requirements do not apply" ... " to conductors specifically provided for elsewhere in this Code."
"specifically provided for" is exactly right here ->
2011-NEC said:
396.10 Uses Permitted
(A) Cable Types. The cable types in Table 396.10(A) shall
be permitted to be installed in messenger-supported wiring
under the conditions described in the article or section...
.... From the table:
Other factory-assembled,
multiconductor control, signal, or
power cables that are identified
for the use
No code section trailing after that, just says
Identified.
If the CMP4 intends for 310 to apply then it should list 310 next to "Other factory-assembled" . The omission of a code section beside "Other factory-assembled" in the table
specifically provides an exemption mentioned in 310.1.
Either way I am not really biased. I am mostly interested determining the ampacity of the XLPE conductors with 90C terminations as per 310.15(C).
Excellent points on the terminations and the splice being "equipment".
The Ilsco tap block is a "fitting" and is therefore equipment.
2011-NEC said:
(1) Equipment Provisions. The determination of termina-
tion provisions of equipment shall be based on 110.14(C)(1)
(a) or (C)(1)(b). Unless the equipment is listed and marked
otherwise, conductor ampacities used in determining equip-
ment termination provisions shall be based on Table
310.15(B)(16) as appropriately modified by 310.15(B)(7).
However I see the equipment is listed and marked
otherwise for 90C terminations.
The manufactures do spec the ampacity as well.
So if any utility EE's on here want to chime in and give there take on how they size triplex and the ratings of there terminations that would be interesting.
Here is the commentary in the handbook:
NEC handbook commentary P 496 (C) 2011 NFPA:
Some of the triplex and quadruplex cable used by utilities as
service-drop cable does not use conductors recognized in
Table 310.104(A) and does not meet the requirements of Ar-
ticle 310. Such triplex and quadruplex cable would be accept-
able only where approved by the authority having jurisdiction.
See 310.15(B) and Table 310.15(B)(20) for two or three
single-insulated conductors supported on a messenger. See
310.15(C) and Informative Annex B, Table B.310.15(B)(20)
(3), for ampacities of conductors for other cable types.
Table B.310.15(B)(20) does not seem to take into account wind velocity where as (21) does.
It would be interesting to see an example calculation using wind velocity.
